This invention relates to a chewing gum base and particularly to a chewing gum base suitable to mixing and joining with a fatty matter such as a chocolate and the like and to a combination of the chewing gum with a fatty matter.
As a chewing gum in combination with chocolate, there have been proposed various types such as a plate or spherical type of chewing gum coated with chocolate, a chocolate coated with a chewing gum, a chocolate containing sugar-coated chewing gums dispersed therein and the like.
The chewing gum with chocolate prepared from the conventional chewing gum base, however, has such the disadvantages that the chewing gum becomes very soft to melt when chewed and tends to be swallowed without leaving any chewing residue.
This softening or melting phenomenon of the gum is caused by such the fatty matter as cacao butter essentially contained in chocolate in an amount of approximately 30 to 35% for which reason the preparation of the chewing gum with chocolate is practically difficult and as a substitute, therefore, has been produced a chewing gum which is flavored with cocoa powder or chocolate flavor free of fatty matter.
In order to overcome the foregoing disadvantages there has been proposed a method of preparing a chewing gum in combination with chocolate in which a content of sugar is restricted to the upper limit of 50% in consideration of the fact that the softening or mixed melting phenomenon of the chewing gum with chocolate is caused not only by action of a plasticizer in the chewing gum but also under the influence of the content of sugar especially more than 50% by weight contained in the chewing gum.
When the sugar content is restricted to less than 50%, however, sweetness and flavoring intensity of the chewing gum become insufficient as compared with the conventional chewing gum with the sugar content of 65 to 80% by weight with such the disadvantages that an amount of the gum base to be used must be increased with much cost and that the softening phenomenon of the gum texture when the chocolate with high content of cacao butter is used may not be avoided even if the melting of the gum could be suppressed.
The inventors have exercised various tests for the chewing gum with a fatty matter which is prepared from various gum base materials and fats on the assumption that the undesired matters might be caused essentially by the plasticizing action (softening action) of the fatty matter in chocolate against the gum base and secondarily by the mixed melting phenomenon of the chewing gum with chocolate containing the plasticizer or sugar and as a result confirmed the fact that a natural resin, a vinyl acetate resin or an ester gum shows a conspicuous plasticizing effect whereas a wax, an emulsifier, a calcium carbonate and a talc have no influence on the softening function on account of fatty matter. Further, it has been confirmed that the natural rubber and the synthetic rubber such as isoprene-isobutylene rubber (IIR), styrene-butadiene rubber (SBR), high molecular polyisobutylene, low molecular polyisobutylene or the like shows a high resistance to the softening function on account of the fatty matter as compared with the natural resin, the vinyl acetate resin and the ester gum.
On the basis of the facts confirmed, the inventors have earnestly studied to improve the resistance to softening of the chewing gum against the fatty matter and have now found out that the resistance to softening may considerably be enhanced by reducing an amount of natural resin, vinyl acetate resin and ester gum while increasing an amount of natural or synthetic rubber to more than 18%. While it has been known that an addition of the rubber gives an appropriate elasticity to the conventional chewing gum, an addition of more than 15% of the rubber makes the product very elastic to cause a hardening phenomenon during the late chewing period. Thus a minimum amount of the rubber has been used in the conventional chewing gum.
Further, it has been found that an amount of the rubber to be used in the chewing gum base depends on an optional selection of a type of fatty matter to be used, a ratio of the gum base to the fatty matter, a gum flavor to be used and the like, but use of more than 40% of the rubber makes the product very elastic to lose the good texture of the chewing gum.